#include<bits/stdc++.h>
using namespace std;
#define lowbit(x) x&(-x)
inline int read(){
    char c = getchar();int x = 0;
    while(c<'0' or c>'9')c = getchar();
    while('0'<=c and c<='9')x = x*10+(c^48),c = getchar();
    return x;
}
void
 write(__int128 x){
    if(x>=10)write(x/10);putchar('0'+x%10);
}
/*
struct node{
    int l,r;
    __int128 mx;
    void add(int x){mx = x;}
}tree[4000005];
void build(int l,int r,int k){
    tree[k].l = l,tree[k].r = r;
    if(l+1 == r){
        return;
    }build(l,l+r>>1,k<<1),build(l+r>>1,r,k<<1|1);
}void upd(int k,int pos,int add){
    int l = tree[k].l,r = tree[k].r,mid = l+r>>1;
    if(l+1 == r){
        tree[k].add(add);return;
    }if(pos<mid)upd(k<<1,pos,add);
    else upd(k<<1|1,pos,add);
    tree[k].mx =max(tree[k<<1].mx,tree[k<<1|1].mx);
}int query(int l,int r,int k){
    int ll = tree[k].l,rr = tree[k].r;
    if(l>=rr or ll>=r)return 0;
    if(l<=ll and rr<=r)return tree[k].mx;
    return max(query(l,r,k<<1),query(l,r,k<<1|1));
}*/
int n;
__int128 tree[1000005];
void upd(int pos,__int128 add){
    for(int i = pos;i<=n;i+=lowbit(i))tree[i] = max(tree[i],add);
}__int128 query(int pos){
    __int128 res = 0;
    for(int i =pos;i>0;i-=lowbit(i))res = max(tree[i],res);
    return res;
}
int t[1000005],v[1000005];
vector<int>pos[1000005];
__int128 a[1000005],dp[1000005];
signed main(){
    cin>>n;
    for(int i = 1;i<=n;i++)t[i] = read();
    for(int i = 1;i<=n;i++)v[i] = read();
    dp[0] = 0;
    for(int i =1;i<=n;i++)a[i] = (__int128)v[i]*t[i];
    for(int i = 1;i<=n;i++)if(i+t[i]<=n)pos[i+t[i]].push_back(i);
    for(int i = 1;i<=n;i++){
    //	cout << i << endl;
        for(int j = 0;j<pos[i].size();j++)upd(pos[i][j],dp[pos[i][j]]);
        dp[i] = a[i]+query(i-t[i]);
    }__int128 res = 0;
    for(int i = 1;i<=n;i++)res = max(res,dp[i]);
    write(res);
    return 0;
}